I had 16M pageviews in 2015 and a hell of a lot less adsense earnings than you :( What's your CPM?
My adsense earnings are terrible though, I've always assumed because the site is more image heavy than text.
Also, find out how many of your users are blocking ads - my site is roughly 5%. However, I am aware of sites that have a younger demographic and 75-80% of their users are blocking ads.